CHYLOTHORAX IN DOMESTIC CAT WITH FELINE INFECTIOUS PERITONITIS: A CASE REPORT

Abstract

Chylothorax is the accumulation of chyle within the pleural cavity and may occur secondary to lymphatic dysfunction. Feline Infectious Peritonitis (FIP) can rarely contribute to this condition through immune-mediated vasculitis and disruption of lymphatic drainage. This case report describes the diagnosis and management of chylothorax associated with FIP in a 7-year-old neutered male domestic cat presented with dyspnea, tachypnea, shallow abdominal breathing, and decreased appetite. Clinical examination, hematological analysis, rapid FIP antibody testing, thoracic radiography, thoracocentesis, and cytological evaluation were performed using a Problem Oriented Approach (POA). Hematological findings revealed leukocytosis, lymphocytosis, granulocytosis, and anemia, indicating systemic inflammation. The FIP antibody test was positive, supporting the suspicion of FIP. Thoracic radiography demonstrated pleural effusion, while thoracocentesis yielded milky-white fluid consistent with chyle. Cytological examination revealed neutrophils, macrophages, lymphocytes, and several bacteria, supporting the diagnosis of chylothorax associated with chronic inflammatory processes. Treatment consisted of antiviral GS-441524, followed by oral molnupiravir, together with cefotaxime, furosemide, aminophylline, and supportive therapy. Clinical improvement was observed during hospitalization, characterized by improved appetite, stabilization of respiratory function, and reduction of pleural effusion on follow-up radiography. This case highlights the importance of a systematic diagnostic approach and early antiviral intervention in achieving favorable outcomes in cats with FIP-associated chylothorax.